dnl Process this file with autoconf to produce a configure script.
AC_INIT(README)

dnl Detect the canonical build and host environments
AC_CONFIG_AUX_DIRS($srcdir/.)
AC_CANONICAL_HOST

dnl Check for tools

AC_PROG_CC

dnl Check for compiler environment

AC_C_CONST

dnl Figure out which math library to use
case "$host" in
    *-*-cygwin* | *-*-mingw32*)
        EXE=".exe"
        MATHLIB=""
        SYS_GL_LIBS="-lopengl32"
        ;;
    *-*-beos* | *-*-haiku*)
        EXE=""
        MATHLIB=""
        SYS_GL_LIBS="-lGL"
        ;;
    *-*-darwin* )
        EXE=""
        MATHLIB=""
        SYS_GL_LIBS="-Wl,-framework,OpenGL"
        ;;
    *-*-aix*)
        EXE=""
        if test x$ac_cv_prog_gcc = xyes; then
            CFLAGS="-mthreads"
        fi
        SYS_GL_LIBS=""
        ;;
    *-*-mint*)
        EXE=""
        MATHLIB=""
        AC_PATH_PROG(OSMESA_CONFIG, osmesa-config, no)
        if test "x$OSMESA_CONFIG" = "xyes"; then
            OSMESA_CFLAGS=`$OSMESA_CONFIG --cflags`
            OSMESA_LIBS=`$OSMESA_CONFIG --libs`
            CFLAGS="$CFLAGS $OSMESA_CFLAGS"
            SYS_GL_LIBS="$OSMESA_LIBS"
        else
            SYS_GL_LIBS="-lOSMesa"
        fi
        ;;
    *-*-qnx*)
        EXE=""
        MATHLIB=""
        SYS_GL_LIBS="-lGLES_CM"
        ;;
    *)
        EXE=""
        MATHLIB="-lm"
        SYS_GL_LIBS="-lGL"
        ;;
esac
AC_SUBST(EXE)
AC_SUBST(MATHLIB)

dnl Check for SDL
SDL_VERSION=2.0.0
AM_PATH_SDL2($SDL_VERSION,
            :,
	    AC_MSG_ERROR([*** SDL version $SDL_VERSION not found!])
)
CFLAGS="$CFLAGS $SDL_CFLAGS"
LIBS="$LIBS -lSDL2_test $SDL_LIBS"

dnl Check for X11 path, needed for OpenGL on some systems
AC_PATH_X
if test x$have_x = xyes; then
    if test x$ac_x_includes = xno || test "x$ac_x_includes" = xNone || test "x$ac_x_includes" = x; then
        :
    else
        CFLAGS="$CFLAGS -I$ac_x_includes"
    fi
    if test x$ac_x_libraries = xno || test "x$ac_x_libraries" = xNone; then
        :
    else
        if test "x$ac_x_libraries" = x; then
            XPATH=""
            XLIB="-lX11"
        else
            XPATH="-L$ac_x_libraries"
            XLIB="-L$ac_x_libraries -lX11"
        fi
    fi
fi

dnl Check for OpenGL
AC_MSG_CHECKING(for OpenGL support)
have_opengl=no
AC_TRY_COMPILE([
 #include "SDL_opengl.h"
],[
],[
have_opengl=yes
])
AC_MSG_RESULT($have_opengl)

dnl Check for OpenGL ES
AC_MSG_CHECKING(for OpenGL ES support)
have_opengles=no
AC_TRY_COMPILE([
 #if defined (__IPHONEOS__)
    #include <OpenGLES/ES1/gl.h>
 #else
    #include <GLES/gl.h>
 #endif /* __QNXNTO__ */
],[
],[
have_opengles=yes
])
AC_MSG_RESULT($have_opengles)

dnl Check for OpenGL ES2
AC_MSG_CHECKING(for OpenGL ES2 support)
have_opengles2=no
AC_TRY_COMPILE([
 #if defined (__IPHONEOS__)
    #include <OpenGLES/ES2/gl.h>
    #include <OpenGLES/ES2/glext.h>
 #else
    #include <GLES2/gl2.h>
    #include <GLES2/gl2ext.h>
 #endif
],[
],[
have_opengles2=yes
])
AC_MSG_RESULT($have_opengles2)

GLLIB=""
GLESLIB=""
GLES2LIB=""
if test x$have_opengles = xyes; then
    CFLAGS="$CFLAGS -DHAVE_OPENGLES"
    GLESLIB="$XPATH -lGLESv1_CM"
fi
if test x$have_opengles2 = xyes; then
    CFLAGS="$CFLAGS -DHAVE_OPENGLES2"
    #GLES2LIB="$XPATH -lGLESv2"
fi
if test x$have_opengl = xyes; then
    CFLAGS="$CFLAGS -DHAVE_OPENGL"
    GLLIB="$XPATH $SYS_GL_LIBS"
fi

AC_SUBST(GLLIB)
AC_SUBST(GLESLIB)
AC_SUBST(GLES2LIB)
AC_SUBST(XLIB)

dnl Check for the SDL2_gfx lib
have_sdlgfx=no
AC_CHECK_LIB(SDL2_gfx, pixelColor , have_sdlgfx=yes)
if test x$have_sdlgfx = xyes; then
    LIBS="$LIBS -lSDL2_gfx"
else
    AC_MSG_ERROR([
*** Unable to find SDL2_gfx library
])
fi

dnl Finally create all the generated files
AC_OUTPUT([Makefile])